They're poking fun at how sometimes you'll find a Python library that does exactly what you want with an interface that feels incredibly intuitive, but you end up finding out it was never updated to work in Python 3.x, only 2.x.
Though I'm not really sure how often that happens these days unless you're trying to write code that's using an old protocol that's fallen out of favor, like IRC, FTP, or Gopher.
Though I'm not really sure how often that happens these days unless you're trying to write code that's using an old protocol that's fallen out of favor, like IRC, FTP, or Gopher.